The invention relates to water heaters, and more particularly to heat traps therefore.
Heat traps for water heaters are known in the art, for example as shown in Nickel U.S. Pat. No. 4,286,573. The heat trap prevents heat loss to the external piping system. At the cold water inlet, the heat trap is provided by a fitting having a ball and a valve seat. The fitting is threadingly connected at one end to an external spud attached to the water heater, and is threadingly connected at the other end to the external cold water inlet pipe.
The present invention provides a cost reduction, and eliminates the extra fitting otherwise required for a heat trap. The present invention provides a heat trap in the dip tube extending downwardly internally in the water heater. Dip tubes are known in the art, for example as shown in U.S. Pat. Nos. 2,764,427, 3,726,475, 3,776,456 and 3,864,234. The dip tube introduces cold water into the water heater at a location spaced below the top of the storage tank.
The present invention modifies the dip tube and provides simple structure for performing the heat trap function within the dip tube, and eliminates the cost of a separate external heat trap fitting otherwise required for such function.
The invention also reduces noise caused by movement of a sealing member performing the heat trap function, by locating the travel stroke of the sealing member entirely within the storage tank.